ABO Industry Standards Flashcards

According to ANSI Z80.1, what is the allowable tolerance for sphere power in single vision lenses with a power of ±0.25D to ±6.50D?

Answer: ±0.13D

ANSI Z80.1 specifies a sphere power tolerance of ±0.13D for prescriptions between ±0.25D and ±6.50D.

What does the term 'vertex distance' refer to in ophthalmic standards?

Answer: The distance from the back surface of the lens to the cornea

Vertex distance is the distance measured from the back (ocular) surface of the ophthalmic lens to the front of the cornea.

Under ANSI Z87.1, occupational and educational eye protection must be marked with which designation to indicate basic impact resistance?

Answer: Z87

The Z87 marking on safety eyewear indicates it meets ANSI Z87.1 basic impact requirements.

What is the minimum refractive index required for a lens to be classified as 'high-index' by industry convention?

Answer: 1.53

By industry convention, lenses with a refractive index of 1.53 or higher are generally classified as high-index.

Which ANSI standard governs the requirements for prescription ophthalmic lenses in the United States?

Answer: ANSI Z80.1

ANSI Z80.1 is the American National Standard for Prescription Ophthalmic Lenses and specifies optical and physical requirements.

What is the ANSI-specified maximum allowable prism imbalance at the near reference point for a single vision lens with prescribed prism?

Answer: 0.33Δ vertical / 0.67Δ horizontal

ANSI Z80.1 allows up to 0.33Δ vertical and 0.67Δ horizontal prism imbalance at the near reference point.

A lens labeled 'UV400' blocks all ultraviolet radiation up to what wavelength?

Answer: 400 nm

UV400 lenses block all UV radiation up to 400 nanometers, covering both UVA and UVB ranges.